nbdsrv.c

   1 #include "config.h"
   2 #include "nbd-debug.h"
   3
   4 #include <nbdsrv.h>
   5
   6 #include <assert.h>
   7 #include <ctype.h>
   8 #include <netdb.h>
   9 #include <stdlib.h>
  10 #include <stdio.h>
  11 #include <string.h>
  12 #include <syslog.h>
  13 #include <unistd.h>
  14
  15 #include <sys/stat.h>
  16 #include <sys/types.h>
  17 #include <sys/socket.h>
  18 #include <treefiles.h>
  19 #include "backend.h"
  20 #ifdef HAVE_SYS_MOUNT_H
  21 #include <sys/mount.h>
  22 #endif
  23
  24 #define LINELEN 256       /**< Size of static buffer used to read the
  25                                authorization file (yuck) */
  26
  27 #include <cliserv.h>
  28
  29 bool address_matches(const char* mask, const struct sockaddr* addr, GError** err) {
  30         struct addrinfo *res, *aitmp, hints;
  31         char *masksep;
  32         char privmask[strlen(mask)+1];
  33         int masklen;
  34         int addrlen = addr->sa_family == AF_INET ? 4 : 16;
  35
  36         assert(addr->sa_family == AF_INET || addr->sa_family == AF_INET6);
  37
  38         strcpy(privmask, mask);
  39
  40         memset(&hints, 0, sizeof(hints));
  41         hints.ai_family = AF_UNSPEC;
  42         hints.ai_flags = AI_NUMERICHOST;
  43
  44         if((masksep = strchr(privmask, '/'))) {
  45                 *masksep = '\0';
  46                 masklen = strtol(++masksep, NULL, 10);
  47         } else {
  48                 masklen = addrlen * 8;
  49         }
  50
  51         int e;
  52         if((e = getaddrinfo(privmask, NULL, &hints, &res))) {
  53                 g_set_error(err, NBDS_ERR, NBDS_ERR_GAI, "could not parse netmask line: %s", gai_strerror(e));
  54                 return false;
  55         }
  56         aitmp = res;
  57         while(res) {
  58                 const uint8_t* byte_s;
  59                 uint8_t* byte_t;
  60                 uint8_t mask = 0;
  61                 int len_left = masklen;
  62                 if(res->ai_family != addr->sa_family) {
  63                         goto next;
  64                 }
  65                 switch(addr->sa_family) {
  66                         case AF_INET:
  67                                 byte_s = (const uint8_t*)(&(((struct sockaddr_in*)addr)->sin_addr));
  68                                 byte_t = (uint8_t*)(&(((struct sockaddr_in*)(res->ai_addr))->sin_addr));
  69                                 break;
  70                         case AF_INET6:
  71                                 byte_s = (const uint8_t*)(&(((struct sockaddr_in6*)addr)->sin6_addr));
  72                                 byte_t = (uint8_t*)(&(((struct sockaddr_in6*)(res->ai_addr))->sin6_addr));
  73                                 break;
  74                 }
  75                 while(len_left >= 8) {
  76                         if(*byte_s != *byte_t) {
  77                                 goto next;
  78                         }
  79                         byte_s++; byte_t++;
  80                         len_left -= 8;
  81                 }
  82                 if(len_left) {
  83                         mask = getmaskbyte(len_left);
  84                         if((*byte_s & mask) != (*byte_t & mask)) {
  85                                 goto  next;
  86                         }
  87                 }
  88                 freeaddrinfo(aitmp);
  89                 return true;
  90         next:
  91                 res = res->ai_next;
  92         }
  93         freeaddrinfo(aitmp);
  94         return false;
  95 }
  96
  97 uint8_t getmaskbyte(int masklen) {
  98         if(masklen >= 8) {
  99                 return 0xFF;
 100         }
 101         uint8_t retval = 0;
 102         for(int i = 7; i + masklen > 7; i--) {
 103                 retval |= 1 << i;
 104         }
 105
 106         return retval;
 107 }
 108
 109 int authorized_client(CLIENT *opts) {
 110         FILE *f ;
 111         char line[LINELEN];
 112
 113         if (opts->server->authname == NULL) {
 114                 msg(LOG_INFO, "No authorization file, granting access.");
 115                 return 1;
 116         }
 117
 118         if ((f=fopen(opts->server->authname,"r"))==NULL) {
 119                 msg(LOG_INFO, "Can't open authorization file %s (%s).",
 120                     opts->server->authname, strerror(errno));
 121                 return 1 ;
 122         }
 123
 124         while (fgets(line,LINELEN,f)!=NULL) {
 125                 char* pos;
 126                 /* Drop comments */
 127                 if((pos = strchr(line, '#'))) {
 128                         *pos = '\0';
 129                 }
 130                 /* Skip whitespace */
 131                 pos = line;
 132                 while((*pos) && isspace(*pos)) {
 133                         pos++;
 134                 }
 135                 /* Skip content-free lines */
 136                 if(!(*pos)) {
 137                         continue;
 138                 }
 139                 if(address_matches(line, (struct sockaddr*)&opts->clientaddr, NULL)) {
 140                         fclose(f);
 141                         return 1;
 142                 }
 143         }
 144         fclose(f);
 145         return 0;
 146 }
 147
 148 /**
 149  * duplicate server
 150  * @param s the old server we want to duplicate
 151  * @return new duplicated server
 152  **/
 153 SERVER* dup_serve(const SERVER *const s) {
 154         SERVER *serve = NULL;
 155
 156         serve=g_new0(SERVER, 1);
 157         if(serve == NULL)
 158                 return NULL;
 159
 160         if(s->exportname)
 161                 serve->exportname = g_strdup(s->exportname);
 162
 163         serve->expected_size = s->expected_size;
 164
 165         if(s->listenaddr)
 166                 serve->listenaddr = g_strdup(s->listenaddr);
 167
 168         if(s->authname)
 169                 serve->authname = g_strdup(s->authname);
 170
 171         serve->flags = s->flags;
 172         serve->virtstyle = s->virtstyle;
 173         serve->cidrlen = s->cidrlen;
 174
 175         if(s->prerun)
 176                 serve->prerun = g_strdup(s->prerun);
 177
 178         if(s->postrun)
 179                 serve->postrun = g_strdup(s->postrun);
 180
 181         if(s->transactionlog)
 182                 serve->transactionlog = g_strdup(s->transactionlog);
 183
 184         if(s->servename)
 185                 serve->servename = g_strdup(s->servename);
 186
 187         if(s->cowdir)
 188                 serve->cowdir = g_strdup(s->cowdir);
 189
 190         serve->max_connections = s->max_connections;
 191
 192         return serve;
 193 }
 194
 195 uint64_t size_autodetect(int fhandle) {
 196         off_t es;
 197         u64 bytes __attribute__((unused));
 198         struct stat stat_buf;
 199         int error;
 200
 201 #ifdef HAVE_SYS_MOUNT_H
 202 #ifdef HAVE_SYS_IOCTL_H
 203 #ifdef BLKGETSIZE64
 204         DEBUG("looking for export size with ioctl BLKGETSIZE64\n");
 205         if (!ioctl(fhandle, BLKGETSIZE64, &bytes) && bytes) {
 206                 return bytes;
 207         }
 208 #endif /* BLKGETSIZE64 */
 209 #endif /* HAVE_SYS_IOCTL_H */
 210 #endif /* HAVE_SYS_MOUNT_H */
 211
 212         DEBUG("looking for fhandle size with fstat\n");
 213         stat_buf.st_size = 0;
 214         error = fstat(fhandle, &stat_buf);
 215         if (!error) {
 216                 /* always believe stat if a regular file as it might really
 217                  * be zero length */
 218                 if (S_ISREG(stat_buf.st_mode) || (stat_buf.st_size > 0))
 219                         return (uint64_t)stat_buf.st_size;
 220         } else {
 221                 DEBUG("fstat failed: %s", strerror(errno));
 222         }
 223
 224         DEBUG("looking for fhandle size with lseek SEEK_END\n");
 225         es = lseek(fhandle, (off_t)0, SEEK_END);
 226         if (es > ((off_t)0)) {
 227                 return (uint64_t)es;
 228         } else {
 229                 DEBUG("lseek failed: %d", errno==EBADF?1:(errno==ESPIPE?2:(errno==EINVAL?3:4)));
 230         }
 231
 232         DEBUG("Could not find size of exported block device: %s", strerror(errno));
 233         return UINT64_MAX;
 234 }
 235
 236 int exptrim(struct nbd_request* req, CLIENT* client) {
 237         /* Don't trim when we're read only */
 238         if(client->server->flags & F_READONLY) {
 239                 errno = EINVAL;
 240                 return -1;
 241         }
 242         /* Don't trim beyond the size of the device, please */
 243         if(req->from + req->len > client->exportsize) {
 244                 errno = EINVAL;
 245                 return -1;
 246         }
 247         /* For copy-on-write, we should trim on the diff file. Not yet
 248          * implemented. */
 249         if(client->server->flags & F_COPYONWRITE) {
 250                 DEBUG("TRIM not supported yet on copy-on-write exports");
 251                 return 0;
 252         }
 253         if (client->server->flags & F_TREEFILES) {
 254                 /* start address of first block to be trimmed */
 255                 off_t min = ( ( req->from + TREEPAGESIZE - 1 ) / TREEPAGESIZE) * TREEPAGESIZE;
 256                 /* start address of first block NOT to be trimmed */
 257                 off_t max = ( ( req->from + req->len ) / TREEPAGESIZE) * TREEPAGESIZE;
 258                 while (min<max) {
 259                         delete_treefile(client->exportname,client->exportsize,min);
 260                         min+=TREEPAGESIZE;
 261                 }
 262                 DEBUG("Performed TRIM request on TREE structure from %llu to %llu", (unsigned long long) req->from, (unsigned long long) req->len);
 263                 return 0;
 264         }
 265         FILE_INFO cur = g_array_index(client->export, FILE_INFO, 0);
 266         FILE_INFO next;
 267         int i = 1;
 268         do {
 269                 if(i<client->export->len) {
 270                         next = g_array_index(client->export, FILE_INFO, i);
 271                 } else {
 272                         next.fhandle = -1;
 273                         next.startoff = client->exportsize;
 274                 }
 275                 if(cur.startoff <= req->from && next.startoff - cur.startoff >= req->len) {
 276                         off_t reqoff = req->from - cur.startoff;
 277                         off_t curlen = next.startoff - reqoff;
 278                         off_t reqlen = curlen - reqoff > req->len ? req->len : curlen - reqoff;
 279                         punch_hole(cur.fhandle, reqoff, reqlen);
 280                 }
 281                 cur = next;
 282                 i++;
 283         } while(i < client->export->len && cur.startoff < (req->from + req->len));
 284         DEBUG("Performed TRIM request from %llu to %llu", (unsigned long long) req->from, (unsigned long long) req->len);
 285         return 0;
 286 }
 287
 288 void myseek(int handle,off_t a) {
 289         if (lseek(handle, a, SEEK_SET) < 0) {
 290                 err("Can not seek locally!\n");
 291         }
 292 }